My father is having asthma from last 22 yrs.. curently his body oxygen level is low and he doesnt feel much hungry.. doctor suggested for oxygen concentrator and we are using that from last 2 days for average 4-5 hr a day.. and his oxygen level is 84.. doctor also said to have IGE test and his IGE level is 1996.1 IU/mL . Can any one suggest input for what is the best we can do to increase his oxygen level n maintain his health